Inter-institutional comparison of treatment practice for cervical cancer with special emphasis on brachytherapy

Purpose
To compare the cervical cancer treatment outcome and toxicities between two different institutions.

Material and methods
We analysed the clinical outcome of cervical cancer patients treated at two different centres from January 2015 to December 2016. Centre A treated 72 patients by external beam radiotherapy (EBRT) to a dose of 45 Gy in 25 fractions followed by intracavitary brachytherapy (ICBT) 6.5 Gy × 4 fractions and centre B treated 89 patients by EBRT to a dose of 50.4 Gy in 28 fractions followed by ICBT 9 Gy × 2 fractions. The local control, distant metastases and treatment toxicities were compared.

Results
The median follow-up in centre A was 12 months and in centre B was 18 months. The median overall treatment time in centre A was 52 days and in centre B was 61 days. The mean equieffective doses in 2 Gy (EQD₂) for high risk target volume (CTV_HR) and point A in centre A were 84.59 and 64.5 Gy, respectively. The mean EQD₂ for point A in centre B was 78.5 Gy. One patient out of 72 (1.38%) had local recurrence in centre A and five patients out of 89 (5.6%) had local recurrence in centre B. Local control in centre A was 98.6% and in centre B was 94.3%. The local recurrence rate was higher in centre B but it was not statistically significant (p = 0.15). One patient developed brain metastasis in centre B. One patient developed grade 3 proctitis in centre A.

Conclusions
A high dose rate brachytherapy fractionation schedule of 6.5 Gy × 4 fractions over 2 days for CTV_HR is associated with reduced overall treatment time, a slightly higher local control rate and lesser dose to OARs compared to 9 Gy × 2 fractions given one week apart to point A.